158 posts? Really?
It's hard to tell much from video, so I'm not going to form an opinion about what Graham can or can't do.

Its not your general take on Aikido videos because: "I would find his position on tsubas much more convincing if the linked videos involved attacks that might at least sting a little bit" so there must be something specific in those videos that make it hard for you "to tell much". What is it?